This is a comparison of a 'Signal Dynamics' 3 LED unit compared to a fixture with a standard 1157 bulb. The 3 LEDs in the tiny fixture are directed 45* apart so as to spread the light and while not as bright as the 1157, are remarkable.
Current draw is .04amps
compared to 1.51amps of the 1157. Don't take much of a solar panel to keep up with that!
....but we're talkin about some pretty good light at 38 times less energy useage, and the bulb ain't likely to burn out in our lifetime.
Color value of the LED is more 'blueish' than the 'yellowish' 1157.
Now, where to mount it???